[Plugin: Contact Form 7] upload folder rights

I’m using last version of CF7 on my WordPress 3.0.1
On wp-config.php, I’ve changed the upload folder location to the default upload folder (wp-content/upload).
But sadly since when, downloading the PDF from this folder doesn’t work anymore.
It seems that changing the upload folded locked the folder.
Please, any clues ?
Thanks to all.